Known display modules for displaying display information (info signs) comprise a backlit light disc in which fixed pictograms are integrated. The region of the light disc in which a pictogram is located is transilluminable. On a printed circuit board that is located behind the light disc there are light-emitting diodes (earlier bi-pin lights). A pictogram is displayed in that activation takes place by applying a supply voltage, which switches on backlighting and renders the pictogram visible by means of transillumination.
The known display modules are associated with a disadvantage in that they are not flexible, because the pictograms are firmly integrated in the light disc. For example, if another pictogram, another combination of pictograms—or another opaque colour is required, a new light disc needs to be specified and qualified, which results in very considerable development expenditure and long delivery times. Since, for example, in some display modules the positions of the light-emitting diodes on the printed circuit board match the respective pictogram in order to obtain optimum transillumination, in the case of new pictograms it is then necessary to develop the printed circuit boards for these display modules anew. If, for example, a pictogram is not unequivocally understandable, then furthermore a brief text explanation is necessary. Since such a text, just like the pictograms, needs to be firmly entered into the light disc, the provision of a multi-language explanation is possible only to a limited extent. Because for reasons of available space the texts need to be very brief, in known display modules at most only text in two languages is possible. Moreover, when the display module is not active, the available free space cannot be used for other purposes.
It can also be considered a disadvantage of the known display modules that they at most comprise two independent chambers that function in the manner described above.
Furthermore, for reasons of space only two pictograms can be incorporated in a light disc. This becomes a disadvantage when, for example, new communication systems such as for example the “GSM on Board” system (global system for mobile communications on board) are used in aircraft. Such communication systems require further pictograms which, for example, cannot be implemented by a simple icon. It will thus be necessary in future to display more than two pictograms, wherein some of the pictograms can become more complex.
As a result of the lack of flexibility and the limit of two simple pictograms and of texts in two languages, the possible information content of the known display modules is very modest indeed.